Observations

Description

Valves are ellipitic in outline and strongly arched about the apical axis. The raphe valve has a narrow, linear axial area with a filiform raphe. The proximal raphe ends are dilated slightly. The distal ends are straight and terminate subterminally. There is a small, irregular central area. A hyaline area occurs on either side of the axial area and forms a naviculoid shape. Striae are fine, punctate, and radiate. The rapheless valve has a narrowly lanceolate central sternum. The areolae are dash-like and offset from one another.

Valves are elliptical in outline and strongly arched about the apical axis. A curved hyaline area is present on either side of the axial area. Striae are fine, punctate and radiate. The rapheless valve has a narrowly lanceolate central sternum. The areolae are dash-like and offset from one another on the rapheless valve.

Compare

Cocconeis pediculus lacks curved, longitudinal hyaline lines on the raphe valve. Cocconeis rugosa has hyaline lines that are interrupted and less defined.